Which two human activities are known to be the greatest contribute to global warming

burning fossil fuels, deforestation and farming.

Explanation:

The burning of fossil fuels and deforestation are the examples of human activities which contribute to global warming. These two activities increase the abundance of greenhouse gases like methane, carbon monoxide, carbon dioxide, nitrous oxides, sulphur oxides in the atmosphere.

Explanation:

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

where's the